Faecal occult blood screening for colorectal cancer: is it cost-effective?

Cost-effectiveness simulation and analysis of colorectal cancer screening in Hong Kong Chinese population: comparison amongst colonoscopy, guaiac and immunologic fecal occult blood testing

Background

The aim of this study was to evaluate the cost-effectiveness of CRC screening strategies from the healthcare service provider perspective based on Chinese population.

Methods

A Markov model was constructed to compare the cost-effectiveness of recommended screening strategies including annual/biennial guaiac fecal occult blood testing (G-FOBT), annual/biennial immunologic FOBT (I-FOBT), and colonoscopy every 10 years in Chinese aged 50 year over a 25-year period. External validity of model was tested against data retrieved from published randomized controlled trials of G-FOBT. Recourse use data collected from Chinese subjects among staging of colorectal neoplasm were combined with published unit cost data ($USD in 2009 price values) to estimate a stage-specific cost per patient. Quality-adjusted life-years (QALYs) were quantified based on the stage duration and SF-6D preference-based value of each stage. The cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER) represented by costs per life-years (LY) and costs per QALYs gained.

Results

In base-case scenario, the non-dominated strategies were annual and biennial I-FOBT. Compared with no screening, the ICER presented $20,542/LYs and $3155/QALYs gained for annual I-FOBT, and $19,838/LYs gained and $2976/QALYs gained for biennial I-FOBT. The optimal screening strategy was annual I-FOBT that attained the highest ICER at the threshold of $50,000 per LYs or QALYs gained.

Conclusion

The Markov model informed the health policymakers that I-FOBT every year may be the most effective and cost-effective CRC screening strategy among recommended screening strategies, depending on the willingness-to-pay of mass screening for Chinese population.

Trial registration

ClinicalTrials.gov Identifier NCT02038283

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1730-y) contains supplementary material, which is available to authorized users.

Collecting and analysing cost data for complex public health trials: reflections on practice

Background

Current guidelines for the conduct of cost-effectiveness analysis (CEA) are mainly applicable to facility-based interventions in high-income settings. Differences in the unit of analysis and the high cost of data collection can make these guidelines challenging to follow within public health trials in low- and middle- income settings.

Objective

This paper reflects on the challenges experienced within our own work and proposes solutions that may be useful to others attempting to collect, analyse, and compare cost data between public health research sites in low- and middle-income countries.

Design

We describe the generally accepted methods (norms) for collecting and analysing cost data in a single-site trial from the provider perspective. We then describe our own experience applying these methods within eight comparable cluster randomised, controlled, trials. We describe the strategies used to maximise adherence to the norm, highlight ways in which we deviated from the norm, and reflect on the learning and limitations that resulted.

Results

When the expenses incurred by a number of small research sites are used to estimate the cost-effectiveness of delivering an intervention on a national scale, then deciding which expenses constitute ‘start-up’ costs will be a nontrivial decision that may differ among sites. Similarly, the decision to include or exclude research or monitoring and evaluation costs can have a significant impact on the findings. We separated out research costs and argued that monitoring and evaluation costs should be reported as part of the total trial cost. The human resource constraints that we experienced are also likely to be common to other trials. As we did not have an economist in each site, we collaborated with key personnel at each site who were trained to use a standardised cost collection tool. This approach both accommodated our resource constraints and served as a knowledge sharing and capacity building process within the research teams.

Conclusions

Given the practical reality of conducting randomised, controlled trials of public health interventions in low- and middle- income countries, it is not always possible to adhere to prescribed guidelines for the analysis of cost effectiveness. Compromises are frequently required as researchers seek a pragmatic balance between rigor and feasibility. There is no single solution to this tension but researchers are encouraged to be mindful of the limitations that accompany compromise, whilst being reassured that meaningful analyses can still be conducted with the resulting data.

Análisis de Costo-Efectividad de las Estrategias de Tamización de Cáncer Colorrectal en Colombia

OBJECTIVE

To evaluate the cost-effectiveness of different screening strategies for colorectal cancer in Colombia.

METHODS

We designed a Markov model to compare the clinical and economic impact in terms of reducing the incidence and mortality from colorectal cancer (CRC). Six screening strategies for adults were compared: fecal occult blood (FOBT) immunochemical and guaiac type, conventional colonoscopy, flexible sigmoidoscopy, and FOBT guaiac and immunochemical type more sigmoidoscopy. We used the third-party payer perspective, including only direct costs, the time horizon was the life expectancy of the Colombian population. We estimated cost-effectiveness ratios (CERs) and incremental cost-effectiveness (ICER). Were performed deterministic sensitivity analysis and probabilistic. We applied a discount rate of 3% in the costs and health outcomes.

RESULTS

The screening strategy more cost-effective was the FOBT biennial guaiac type. The cost per life year gained was US$10,347.37, US$18,380.64, and US$45,158.05. For FOBT guaiac biennial, FOBT guaiac annual and FOBT inmunoquímica biennial respectively. The ICER is sensitive to the percentage of false positive test for FOBT guaiac type values greater than 10%, and the cost of the test.

CONCLUSIONS

The screening strategy more cost-effective for Colombia is the FOBT biennial guaiac type, using as a threshold the gross domestic product (GDP) per capita in Colombia.

Cost-effectiveness of colorectal cancer screening

Colorectal cancer is an important public health problem. Several screening methods have been shown to be effective in reducing colorectal cancer mortality. The objective of this review was to assess the cost-effectiveness of the different colorectal cancer screening methods and to determine the preferred method from a cost-effectiveness point of view. Five databases (MEDLINE, EMBASE, the Cost-Effectiveness Analysis Registry, the British National Health Service Economic Evaluation Database, and the lists of technology assessments of the Centers for Medicare and Medicaid Services) were searched for cost-effectiveness analyses published in English between January 1993 and December 2009. Fifty-five publications relating to 32 unique cost-effectiveness models were identified. All studies found that colorectal cancer screening was cost-effective or even cost-saving compared with no screening. However, the studies disagreed as to which screening method was most effective or had the best incremental cost-effectiveness ratio for a given willingness to pay per life-year gained. There was agreement among studies that the newly developed screening tests of stool DNA testing, computed tomographic colonography, and capsule endoscopy were not yet cost-effective compared with the established screening options.

Population-based screening for colorectal cancer with faecal occult blood test--do we really have enough evidence?

INTRODUCTION

Population-based randomised controlled trials (RCT) have shown that invitation to biennial screening with faecal occult blood testing (FOBT) during 10 or more years reduced colorectal cancer-specific mortality. These results have stimulated plans to introduce mass screening in various countries; however, none of these trials has been able to show any reduction of total mortality, which should be expected with reduced disease-specific mortality in a RCT.

METHODS

The aim of this review is to analyse, in more detail, the findings in these trials. The results of the trials have, in this review, been systematised and discussed in the context of potential bias, validity and effectiveness.

RESULTS

It is found that the reduced cancer-specific mortality is modest and that the clinical significance may be discussed. The number of persons needed to be invited for multiple screening rounds to avoid one death in colorectal cancer (CRC) is high, ranging from about 600 to 1,200. A remarkable finding is that only one fourth of the carcinomas in those invited to the screening were actually detected by this intervention. The absence of reduced total mortality in all series is a serious problem and evokes questions about the validity in determination of cause of death. None of these trials showed any effect on incidence of CRC by removal of precancerous adenomas.

CONCLUSIONS

It seems reasonable to conclude that the scientific evidence to support introduction of population-based screening programmes with FOBT appears not yet strong enough. In addition, harm/benefit and cost/effectiveness ratios are not well determined.

Repeat participation in colorectal cancer screening utilizing fecal occult blood testing: a community-based project in a rural setting

BACKGROUND AND AIM

To investigate participation in a second round of colorectal cancer screening using a fecal occult blood test (FOBT) in an Australian rural community, and to assess the demographic characteristics and individual perspectives associated with repeat screening.

METHODS

Potential participants from round 1 (50-74 years of age) were sent an intervention package and asked to return a completed FOBT (n = 3406). Doctors of participants testing positive referred to colonoscopy as appropriate. Following screening, 119 participants completed qualitative telephone interviews. Multivariable logistic regression models evaluated the association between round-2 participation and other variables.

RESULTS

Round-2 participation was 34.7%; the strongest predictor was participation in round 1. Repeat participants were more likely to be female; inconsistent screeners were more likely to be younger (aged 50-59 years). The proportion of positive FOBT was 12.7%, that of colonoscopy compliance was 98.6%, and the positive predictive value for cancer or adenoma of advanced pathology was 23.9%. Reasons for participation included testing as a precautionary measure or having family history/friends with colorectal cancer; reasons for non-participation included apathy or doctors' advice against screening.

CONCLUSION

Participation was relatively low and consistent across rounds. Unless suitable strategies are identified to overcome behavioral trends and/or to screen out ineligible participants, little change in overall participation rates can be expected across rounds.

Simulation of colorectal cancer screening: what we do and do not know and does it matter

Simulation modelling is increasingly used to inform decision-making on screening, including colorectal cancer screening strategies. The strength of simulation is its ability to handle complexity and to identify the implications of uncertainty in a formal, documented, reproducible and consistent way. Important specific uncertainties concerning colorectal cancer screening are the dwell time of adenomas and the associated sensitivity of the various tests. Concerning these issues, for distal colorectal neoplasia, knowledge has been greatly increased by the recent availability of the once only sigmoidoscopy randomised trial results. Other uncertainties concern the quality of life effects of screening, diagnostic and surveillance colonoscopies, and the true total costs of the various screening modalities in a routine high throughput efficient setting. A limitation of simulation of screening is that complexity leads to lack of insight and understanding into the models used, and therefore a lack of sound criticism, acceptance and use amongst decision makers. Modellers are currently focussing on ways to make models and the implications of assumptions more transparent. Thus it is important to further develop the quality and acceptability of simulation, especially that for colorectal cancer screening.

Cost-effectiveness of screening for colorectal cancer in France using a guaiac test versus an immunochemical test

Objectives: The aim of this study was to compare the cost and the effectiveness of two biennial fecal occult blood screening tests for colorectal cancer: a guaiac nonrehydrated test (G-FOBT) and an immunochemical test (I-FOBT) with the absence of screening.

Methods: A Markov model was developed to compare these strategies in a general population of subjects aged 50 to 74 over a 20-year period.

Results: Compared with the absence of screening, G-FOBT and I-FOBT were associated with a decrease in colorectal cancer mortality of 17.4 percent and 25.2 percent, respectively. With regard to cost-effectiveness, expressed as cost per life-year gained, I-FOBT was the most effective and most costly alternative. Compared with no screening, G-FOBT and I-FOBT presented similar discounted incremental cost-effectiveness ratios: €2,739 and €2,819 respectively per life-year gained. When compared with G-FOBT, I-FOBT presented an incremental cost-effectiveness ratio of €2,988 per life-year gained. Sensitivity analyses showed the strong influence of the I-FOBT lead time, of the participation rate to screening for I-FOBT, and of the purchase price of the I-FOBT on the discounted incremental cost-effectiveness ratios.

Conclusions: Compared with the absence of screening and with G-FOBT, the biennial two-stool immunochemical test can be considered a promising method for mass screening for colorectal cancer.

The dynamics of colorectal cancer management in 17 countries

This paper discusses the current care management arrangements for colorectal cancer (CRC) in 16 OECD countries plus the Russian Federation by analysing data sources, the uptake of screening and surveillance, the available capacity in endoscopy services, the treatment pathways in medical treatment, as well as the type and availability of pharmaceutical care. The paper highlights significant variations in practice across the 17 countries. Common themes emerge from each of these practices and standards in terms of political interest in policies and awareness of CRC (both of which need to be enhanced), affordability (in terms of scarcity of resources in some countries and out-of-pocket payments for parts of the overall treatment process), access (in terms of the significant variation that has been observed within and across countries with regard to diagnostics, treatment and certain pharmaceuticals) and quality of CRC services (which may arise due to variations in treatment and pharmaceutical guidelines as well as minimal monitoring). When considering policy options for the future, it is important to, first, improve data collection both within as well as across countries through international co-operation; second, it is critical to have greater national and international support for cancer screening activities proven to be effective and cost-effective; third, endoscopy capacity in individual countries needs to be improved, also allowing more choice to ensure timely diagnosis, regardless of screening activities; fourth, public and political awareness needs to be enhanced as it is the key to improving CRC outcomes; fifth, where appropriate, to give consideration to the principles of equity, human dignity and disease severity, among others, when deciding on the uptake of new (targeted) treatments, rather than base decisions solely on cost-effectiveness criteria; and sixth, to firm up national guidelines including screening, diagnosis, treatment, pharmaceutical treatments and surveillance, with a view to enhancing their timeliness, evidence-base and free access to all.

Systematic review of economic evidence for the detection, diagnosis, treatment, and follow-up of colorectal cancer in the United Kingdom

Objectives: The aim of this study was to examine the availability and consistency of economic evidence for the detection, diagnosis, treatment, and follow-up of colorectal cancer.

Methods: A systematic review of UK economic evaluations of colorectal cancer interventions was undertaken. Searches were undertaken across ten electronic databases. Studies were critically appraised through reference to a conceptual model of UK colorectal cancer services.

Results: Forty-seven studies met the inclusion criteria. There is a substantial economic evidence base surrounding population-level colorectal screening, surgical procedures, and cytotoxic therapies for the adjuvant and palliative treatment of colorectal cancer. There is limited evidence concerning the diagnosis of suspected colorectal cancer, curative treatments for metastatic disease and follow-up regimens for nonmetastatic disease. No studies were identified relating to the economics of radiotherapy, surveillance of increased-risk groups, end-of-life care, or the management of hereditary colorectal cancer. Where evidence is available, studies are subject to important differences concerning treatment options, decision criteria, and incongruent assumptions concerning the disease and its management.

Conclusions: Across many aspects of the colorectal cancer service, current practice appears to have emerged without the consideration or support of economic evidence. There is a need to develop a common understanding how colorectal cancer models should be structured and implemented.

Validation of a Predictive Model for Automated External Defibrillator Placement in Rural America

OBJECTIVE

The development of Automated External Defibrillators (AEDs) to treat out-of-hospital cardiac arrest (OOHCA) has greatly expanded the availability of life saving defibrillatory shocks in various settings. However, placement of AEDs in rural areas remains perplexing since OOHCAs are rare and unpredictable. We set out to develop a cost-effective rural AED placement model and to test the validity of the resulting model using OOHCAs attended by EMS.

METHODS

DESIGN

A population-based cross-sectional study. Analytic Plan: An exhaustive literature search was conducted to identify community attributes correlated with successful placement of AEDs in rural regions. Identified attributes were characterized using U.S. Census and CDC heart disease mortality data to estimate the potential risk for AED use and applied this estimate to rural census tracts in all 50 states. Based upon risk, AEDS were assigned to each tract using a first responder model and cost effectiveness was assessed. Using Utah State EMS data, the predicted placement of AEDs in each tract was validated using the actual number of OOHCAs attended by EMS.

RESULTS

A total of 14,586 rural census tracts in 50 U.S. states were evaluated. On average, 2,600 AEDs were situated within each state. AED placement in rural areas proved as cost effective as health screening programs. In Utah, predicted AED placement correlated with the frequency of OOHCAs attended by EMS personnel (rho= 0.55, p < 0.001).

CONCLUSIONS

The resulting model illustrates one potential way to determine the most beneficial location for rural AED placement.

Calibration methods used in cancer simulation models and suggested reporting guidelines

Increasingly, computer simulation models are used for economic and policy evaluation in cancer prevention and control. A model's predictions of key outcomes, such as screening effectiveness, depend on the values of unobservable natural history parameters. Calibration is the process of determining the values of unobservable parameters by constraining model output to replicate observed data. Because there are many approaches for model calibration and little consensus on best practices, we surveyed the literature to catalogue the use and reporting of these methods in cancer simulation models. We conducted a MEDLINE search (1980 through 2006) for articles on cancer-screening models and supplemented search results with articles from our personal reference databases. For each article, two authors independently abstracted pre-determined items using a standard form. Data items included cancer site, model type, methods used for determination of unobservable parameter values and description of any calibration protocol. All authors reached consensus on items of disagreement. Reviews and non-cancer models were excluded. Articles describing analytical models, which estimate parameters with statistical approaches (e.g. maximum likelihood) were catalogued separately. Models that included unobservable parameters were analysed and classified by whether calibration methods were reported and if so, the methods used. The review process yielded 154 articles that met our inclusion criteria and, of these, we concluded that 131 may have used calibration methods to determine model parameters. Although the term 'calibration' was not always used, descriptions of calibration or 'model fitting' were found in 50% (n = 66) of the articles, with an additional 16% (n = 21) providing a reference to methods. Calibration target data were identified in nearly all of these articles. Other methodological details, such as the goodness-of-fit metric, were discussed in 54% (n = 47 of 87) of the articles reporting calibration methods, while few details were provided on the algorithms used to search the parameter space. Our review shows that the use of cancer simulation modelling is increasing, although thorough descriptions of calibration procedures are rare in the published literature for these models. Calibration is a key component of model development and is central to the validity and credibility of subsequent analyses and inferences drawn from model predictions. To aid peer-review and facilitate discussion of modelling methods, we propose a standardized Calibration Reporting Checklist for model documentation.

Treatment of the elderly colorectal cancer patient: SIOG expert recommendations

Colorectal cancer (CRC) is one of the commonest malignancies of Western countries, with approximately half the incidence occurring in patients >70 years of age. Elderly CRC patients, however, are understaged, undertreated and underrepresented in clinical trials. The International Society of Geriatric Oncology created a task force with a view to assessing the potential for developing guidelines for the treatment of elderly (geriatric) CRC patients. A review of the evidence presented by the task force members confirmed the paucity of clinical trial data in elderly people and the lack of evidence-based guidelines. However, recommendations have been proposed on the basis of the available data and on the emerging evidence that treatment outcomes for fit, elderly CRC patients can be similar to those of younger patients. It is hoped that these will pave the way for formal treatment guidelines based upon solid scientific evidence in the future.

Predictive factors of years of potential life lost by colorectal cancer

OBJECTIVE

To evaluate the impact of colorectal cancer (CRC) by estimating the years of potential life lost (YPLL) by this neoplasm in a cohort of patients, as well as to define the predictive factors of YPLL.

METHODS

A descriptive cross-sectional study of 980 consecutive patients diagnosed and treated because of CRC in our institution between 1985 and 2002 was carried out. Demographic, clinical, pathological, surgical, hospital stay, complications, and mortality variables were recorded. The primary endpoint of this study was to calculate individual YPLL. Univariate analysis was performed to compare each independent variable with the variable YPLL. All clinically relevant variables significantly associated with YPLL were included in an ordinal regression model to identify independent factors prognostic of YPLL.

RESULTS

The final study sample was 794 patients, 413 (52%) men and 381 (48%) women, mean age 65.3 years [confidence interval (CI) 95%: 64.4-66.2 years; SD: 12.8]. The mean global YPLL for the 351 patients who died of CRC was 15.2 years (SD: 10.7; CI 95%: 14.1-16.3). Lower age [odds ratio (OR)=0.98; CI 95%: 0.97-0.98], male sex (OR=1.19; CI 95%: 1.00-1.43), lower tumor, nodes, metastasis (TNM) stage (OR=0.29; CI 95%: 0.24-0.35), and rectum localization of the tumor (OR=1.37; CI 95%: 1.14-1.64) were independent prognostic factors for YPLL.

CONCLUSION

In our community, the mean number of YPLL by CRC exceeds 15 years. Lower age, male sex, higher TNM stage, and rectum localization are negative predictors of YPLL.

Screening pregnant women for autoimmune thyroid disease: a cost-effectiveness analysis

OBJECTIVE

Untreated maternal hypothyroidism during pregnancy can have adverse consequences on maternal health and child intelligence quotient (IQ). Our objective was to examine the cost-effectiveness of screening pregnant women for autoimmune thyroid disease.

DESIGN

We developed a state-transition Markov model and performed a cost-effectiveness analysis of screening pregnant US women, aged 15-45 years, with no known history of thyroid disease, in the first trimester.

METHODS

Three strategies were compared: 1) no screening, 2) one-time screening using anti-thyroid peroxidase (anti-TPO) antibodies, and 3) one-time screening using TSH. Screening tests were added to the laboratory tests of the first prenatal visit. Abnormal screening tests were followed by further testing and subsequent thyroxine treatment of hypothyroid women.

RESULTS

Screening pregnant women in the first trimester using TSH was cost-saving compared with no screening. Screening using anti-TPO antibodies was cost-effective compared with TSH screening with an incremental cost-effectiveness ratio of $15,182 per quality-adjusted life year. Screening using TSH remained cost-saving across a wide range of ages at screening, costs of treatment, and probabilities of adverse outcomes. The cost-effectiveness of anti-TPO screening compared with TSH screening was mostly influenced by the probability of diagnosing hypothyroidism in unscreened subjects or subjects with a normal screening test. Screening remained highly cost-effective in scenarios where we assumed no improvement of child IQ outcomes by levothyroxine treatment.

CONCLUSION

Screening all pregnant women for autoimmune thyroid disease in the first trimester is cost-effective compared with not screening.

A cost analysis of colonoscopy using microcosting and time-and-motion techniques

BACKGROUND

The cost of an individual colonoscopy is an important determinant of the overall cost and cost-effectiveness of colorectal cancer screening. Published cost estimates vary widely and typically report institutional costs derived from gross-costing methods.

OBJECTIVE

Perform a cost analysis of colonoscopy using micro-costing and time-and-motion techniques to determine the total societal cost of colonoscopy, which includes direct health care costs as well as direct non-health care costs and costs related to patients' time. The design is prospective cohort. The participants were 276 contacted, eligible patients who underwent colonoscopy between July 2001 and June 2002, at either a Veterans' Affairs Medical Center or a University Hospital in the Southeastern United States.

MAJOR RESULTS

The median direct health care cost for colonoscopy was $379 (25%, 75%; $343, $433). The median direct non-health care and patient time costs were $226 (25%, 75%; $187, $323) and $274 (25%, 75%; $186, $368), respectively. The median total societal cost of colonoscopy was $923 (25%, 75%; $805, $1047). The median direct health care, direct non-health care, patient time costs, and total costs at the VA were $391, $288, $274, and $958, respectively; analogous costs at the University Hospital were $376, $189, $368, and $905, respectively.

CONCLUSION

Microcosting techniques and time-and-motion studies can produce accurate, detailed cost estimates for complex medical interventions. Cost estimates that inform health policy decisions or cost-effectiveness analyses should use total costs from the societal perspective. Societal cost estimates, which include patient and caregiver time costs, may affect colonoscopy screening rates.

Cost-effectiveness of automated external defibrillators in public places: pro

PURPOSE OF REVIEW

Placement of automated external defibrillators in public facilities is a cost-effective treatment for out-of-hospital cardiac arrests. This review describes the literature citing the benefits of early defibrillation, ease of use, and relative cost of automated external defibrillators.

RECENT FINDINGS

Placement of automated external defibrillators in public places was recommended by the American Heart Association in the early 1990s. Compared with waiting for traditional emergency medical services, immediate use of automated external defibrillators by laypersons can dramatically increase survival to hospital discharge rates. Placement of automated external defibrillators at locations such as casinos, airports, and airplanes that are frequented by large numbers of at-risk people is cost-effective compared with other economically acceptable health measures. Studies using simulations to predict numbers of quality-adjusted life years that would be gained from implementation of public access defibrillation programs in high-incidence locations find that the cost would be less than the typically acceptable 50,000 dollars per quality-adjusted life year. The cost estimates, however, depend on the incidence of cardiac arrest at the sites, with low-incidence sites being prohibitively expensive.

SUMMARY

Automated external defibrillators appear to be cost-effective in locations with high incidences of cardiac arrest.

[Cost-effectiveness of colorectal cancer screening]

Colorectal cancer (CRC) screening in France is based on a faecal occult blood test every two years in average risk subjects 50-74 years of age while other endoscopic or non-endoscopic screening methods are used in Europe and in the USA. Beside the reduced incidence of and mortality from CRC found in available studies, cost-effectiveness data need to be taken into account. Because of the delay between randomized controlled trials and clinical results, transitional probabilistic models of screening programs are useful for public health policy makers. The aim of the present review was to promote the implementation of cost-effectiveness studies, to provide a guide to analyze cost-effectiveness studies on CRC screening and, to propose a French cost effectiveness study comparing CRC screening strategies. Most of these trials were performed by US or UK authors and demonstrate that the incremental cost-effectiveness ratio varies between 5 000 and 15 000 US dollars/one year life gained, with wide variations: these results were highly dependent on the unit costs of the different devices as well as the predictive values of the screening tests. Although CRC screening programs have been implemented in several administrative districts of France since 2002, and the results of these randomized controlled trials using fecal occult blood have been updated, cost-effectiveness criteria need to be integrated; especially since the results of screening campaigns based on other tools such as flexible sigmoidoscopy should be available in 2007.

Re-interpreting the data on the cost and effectiveness of population screening for colorectal cancer in Australia

Three studies report estimates of the cost and effectiveness of alternate strategies for screening the average-risk Australian population for colorectal cancer. The options considered are faecal occult blood testing, double contrast barium enema, sigmoidoscopy and colonoscopy. At present, there is no consensus over which screening method is optimal by the economic criterion. Also, the existing studies report a mixture of average and incremental cost-effectiveness ratios derived from data collected between 1994 and 2002. We suggest average cost-effectiveness ratios are not useful for decision-making and illustrate how they differ from the preferred incremental cost-effectiveness ratio. We then update the cost data reported in the three studies to 2002 prices and calculate incremental cost-effectiveness ratios where not previously available. Our re-analysis of one study contradicts the conclusions drawn by the authors, who had only calculated average cost-effectiveness ratios. In particular, we find their recommendation of population screening with colonoscopy would cause, annually, between 33 and 1,322 years of life to be lost and between $M17 and $M87 to be wasted. Based on updated cost data and the incremental analysis, our findings indicate that population screening using biennial faecal occult blood testing ($39,459 per life-year gained), annual faecal occult blood testing ($30,556 per life-year gained) and colonoscopy ($26,587 per life-year gained) are cost-effective. Hence, the decision over which method of screening is optimal remains ambiguous across the three studies. We recommend policy-makers choose the study they believe produces the most accurate estimates of cost and health effect, identify their willingness to pay for health benefits and consider other issues relevant to the decision.

Colorectal cancer screening in Australia: an economic evaluation of a potential biennial screening program using faecal occult blood tests

OBJECTIVE

To evaluate whether the introduction of a national, co-ordinated screening program using the faecal occult blood test represents 'value-for-money' from the perspective of the Australian Government as third-party funder.

METHODS

The annual equivalent costs and consequences of a biennial screening program in 'steady-state' operation were estimated for the Australian population using 1996 as the reference year. Disability-adjusted life years (DALYs) and the years of life lost (YLLs) averted, and the health service costs were modelled, based on the epidemiology and the costs of colorectal cancer in Australia together with the mortality reduction achieved in randomised controlled trials. Uncertainty in the model was examined using Monte Carlo simulation methods.

RESULTS

We estimate a minimum or 'base program' of screening those aged 55 to 69 years could avert 250 deaths per annum (95% uncertainty interval 99-400), at a gross cost of dollarsA55 million (95% UI dollarsA46 million to dollarsA96 million) and a gross incremental cost-effectiveness ratio of dollarsA17,000/DALY (95% UI dollarsA13,000/DALY to dollarsA52,000/DALY). Extending the program to include 70 to 74-year-olds is a more effective option (cheaper and higher health gain) than including the 50 to 54-year-olds.

CONCLUSIONS

The findings of this study support the case for a national program directed at the 55 to 69-year-old age group with extension to 70 to 74-year-olds if there are sufficient resources. The pilot tests recently announced in Australia provide an important opportunity to consider the age range for screening and the sources of uncertainty, identified in the modelled evaluation, to assist decisions on implementing a full national program.

Cost-effectiveness analysis of fecal occult blood screening for colorectal cancer

OBJECTIVES

Clinical trials have demonstrated that fecal occult blood screening for colorectal cancer can significantly reduce mortality. However, to be deemed a priority from a public health policy perspective, any new program must prove itself to be cost-effective. The objective of this study was to assess the cost-effectiveness of screening for colorectal cancer using a fecal occult blood screening test, the Hemoccult-II, in a cohort of 100,000 asymptomatic individuals 50-74 years of age.

METHODS

A decision analysis model using a Markov approach simulates the trajectory of the cohort allocated either to screening or no screening over a 20-year period through several health states. Clinical and economic data used in the model came from the Burgundy trial, French population-based studies, and Registry data.

RESULTS

Modeling biennial screening versus the absence of screening over a 20-year period resulted in a 17.7 percent mortality reduction and a discounted incremental cost-effectiveness ratio of 3357 Euro per life-year gained among individuals 50-74 years of age. Sensitivity analyses performed on epidemiological and economic data showed the strong impact on the results of colonoscopy cost, of compliance to screening, and of specificity of the screening test.

CONCLUSIONS

Cost-effectiveness estimates and sensitivity analyses suggest that biennial screening for colorectal cancer with fecal occult blood test could be recommended from the age of 50 until 74. Our findings support the attempts to introduce large-scale population screening programs.

Cost-effectiveness of screening for colorectal cancer: evidence from the Nottingham faecal occult blood trial

OBJECTIVES

To estimate the cost-effectiveness of faecal occult blood (FOB) screening for colorectal cancer within the Nottingham trial.

SETTING

A randomised controlled trial (1981-present) of 153,000 subjects, of whom approximately half were offered biennial FOB testing over up to five screening rounds.

METHODS

The additional costs of participation in screening relative to symptomatic presentation were calculated by combining the results of (i) a comprehensive audit of resource use on the part of subjects within the trial, (ii) previously-established unit costs for each of the procedures involved. Life expectancy gains were estimated from a survival analysis of those trial subjects who had been diagnosed with cancer (screening participants vs controls).

RESULTS

The cost of screening under the Nottingham trial protocol was pound 5290 per cancer detected (at 2002 prices). Under conservative assumptions, the incremental cost per life year gained as a result of screening was pound 1584 (Confidence Interval [CI]:717 to 8612).

Cost effectiveness analysis of intensive versus conventional follow up after curative resection for colorectal cancer

OBJECTIVE

To determine the cost effectiveness of intensive follow up compared with conventional follow up in patients with colorectal cancer.

DESIGN

Incremental cost effectiveness analysis recognising differences in follow up strategies, based on effectiveness data from a meta-analysis of five randomised trials.

SETTING

United Kingdom.

MAIN OUTCOME MEASURES

Taking a health service perspective, estimated incremental costs effectiveness ratios for each life year gained for five trials and four trials designed for early detection of extramural recurrences (targeted surveillance).

RESULTS

Based on five year follow up, the numbers of life years gained by intensive follow up were 0.73 for the five trial model and 0.82 for the four trial model. For the five trials, the adjusted net (extra) cost for each patient was 2479 pounds sterling (3550 euros; 4288 dollars) and for each life year gained was 3402 pounds sterling, substantially lower than the current threshold of NHS cost acceptability (30 000 pounds sterling). The corresponding values for the four trial model were 2529 pounds sterling and 3077 pounds sterling, suggesting that targeted surveillance is more cost effective. The main predictor of incremental cost effectiveness ratios was surveillance costs rather than treatment costs. Judged against the NHS threshold of cost acceptability, the predicted incremental cost threshold was ninefold and the effectiveness threshold was 3%.

CONCLUSIONS

Based on the available data and current costs, intensive follow up after curative resection for colorectal cancer is economically justified and should be normal practice. There is a continuing need to evaluate the efficacy of specific surveillance tools: this study forms the basis for economic evaluations in such trials.

Fecal occult blood screening--trial evidence, practice and beyond

Colorectal cancer is a leading cause of morbidity and mortality in Western countries. Primary prevention and early detection of this malignancy has been shown in multiple research set-ups, and using different modalities, to be effective in reducing the incidence and mortality rates of this disease. Three randomized controlled trials have been conducted over the last 30 years to evaluate the efficacy of periodic screening with fecal occult blood tests (FOBT). These studies have consistently demonstrated mortality reduction with biennial as well as annual testing after 8-18 years of follow-up. A significant primary prevention effect through reduction of colorectal cancer incidence was also reported. The results of the Israeli population-based screening program using Hemoccult Sensa show that it is possible to achieve a high detection rate in a well-organized community set-up and, in addition, also a shift in tumor stage towards smaller tumors, a low positivity rate, and an acceptable false positivity rate. FOBT is cheap and performs very well in cost effectiveness analyses evaluating the cost of detecting one cancer. This is quite a rare situation where mortality reduction can be achieved with a simple rather than a sophisticated technology. Research to further enhance the cancer detection capabilities of FOBT through the incorporation of molecular testing of the stool for tumor genes is underway. Multiple policymakers are already recommending this procedure for routine screening of average risk population. Taking their recommendations into action is of major importance.

Colorectal cancer, screening and survival: the influence of socio-economic deprivation

OBJECTIVES

To determine the extent to which socio-economic deprivation explains colorectal cancer prevalence, subject participation in screening, and postoperative survival and life expectancy.

METHODS

Regression analyses of clinical data from a large randomized controlled trial, augmented by geographical-based indices of deprivation.

RESULTS

Deprivation appears to exert no significant impact on colorectal cancer prevalence but is a major factor explaining subject participation in screening. Cancer detection at later stages reduces life expectancy at time of treatment. Females from more-deprived areas have poorer post-treatment life expectancies and survival prospects, independently of their screening behaviour.

CONCLUSIONS

Screening increases the chances of having a cancer treated at an earlier stage, and treatment at an earlier stage is associated with longer subsequent life expectancy. However, those from more-deprived areas are less likely to accept an invitation to be screened.

Effectiveness and cost of screening for abdominal aortic aneurysm: results of a population screening program

OBJECTIVES

We undertook this study to calculate the cost per life-year gained in the first round of a screening program for abdominal aortic aneurysm (AAA) and to estimate the costs in a subsequent round.

METHODS

This was an intervention study, with follow-up for ruptured aneurysms. Men older than 50 years were screened for asymptomatic AAA. Outcome measures included cost per life-year saved and number of men needed to be screened to save one life.

RESULTS

The incidence of ruptured AAA was 2.6 per 10,000 person- years in the screening group and 7.1 per 10,000 person-years in the control group. Screening is estimated to have prevented 10.8 ruptured AAA and 8 deaths per year, gaining 51 life-years per year for the study population, and to have reduced the incidence of ruptured AAA by 64% (95% CI, 42%-77%). Each life-year gained during the first screening round cost $1107. To save one life, 1000 men need to be screened and 5 elective operations performed. We predict that a second round of screening can be cost neutral.

CONCLUSIONS

The cost-effectiveness of screening for AAA compares favorably with screening programs for other disorders in adults.

A comparison of two methods for eliciting contingent valuations of colorectal cancer screening

Willingness-to-pay (WTP) is being used increasingly in health technology assessment, although a number of methodological issues remain unresolved. Using data obtained from a randomised questionnaire survey, we investigated the metrical properties of two WTP formats, the open-ended question versus the payment scale, in the context of screening for colorectal cancer. Approximately, 2800 responses were analysed. Household income, attitudes toward health promotion and personal risk perceptions were the principal determinants of the nature and value of response. In comparison with the open-ended format, the payment scale achieved a higher completion rate and generated higher valuations. We believe that a framing effect is the most plausible explanation for these differences in performance. In contrast to previous findings, we do not find subjects' perceptions of the resource cost of interventions to be a convincing explanation for either their WTP values or inconsistencies between values and preferences. Although a proportion of respondents protested at the notion of valuation, the majority offer positive valuations, although typically of a lower value that non-protesters.

Eliciting willingness to pay: comparing closed-ended with open-ended and payment scale formats

Willingness to pay (WTP) is increasingly being used as a measure of valuation in health technology assessment. A variety of formats for eliciting values are available, although the relative virtues of each remain the subject of methodological controversy. This article compares valuation results obtained using a WTP survey instrument in a closed-ended format with those obtained from instruments using open-ended and payment scale formats. Samples of subjects were drawn from a general population, and all were asked to value the same intervention--alternative methods of screening for colorectal cancer. It was discovered that, whereas the open-ended and payment scale formats produced broadly similar valuations, the closed-ended format produced significantly higher WTP valuations and different justifications for those valuations. It is hypothesized that anchoring and yea-saying effects explain these differences and that the closed-ended format triggers a different response mode in subjects.

A simulation model for evaluating the medical and economic outcomes of screening strategies for colorectal cancer

Mathematical models have been shown to be useful in predicting the cost-effectiveness of cancer screening programmes. We designed a computer macro-simulation model aimed at predicting the cost-effectiveness of alternative colorectal cancer screening strategies. This model was built to determine the cost-effectiveness of a biennial screening programme using the Hemoccult test in Burgundy (France). It was validated with data from the Danish randomized study. Estimates of our model showed an extremely close concordance with observed results in the Danish study. The observed mortality reduction was 18.0% and the estimated mortality reduction was 18.4%. Preliminary data from the Burgundy study predict a 14.6% colorectal cancer mortality reduction after 10 years. Sensitivity analyses were performed with different assumptions regarding the participation rates and the lead-time. This model can serve to assess the cost-effectiveness of a variety of screening modalities.

The limited incorporation of economic analyses in clinical practice guidelines

BACKGROUND

Because there is increasing concern that economic data are not used in the clinical guideline development process, our objective was to evaluate the extent to which economic analyses are incorporated in guideline development.

METHODS

We searched medline and HealthSTAR databases to identify English-language clinical practice guidelines (1996-1999) and economic analyses (1990-1998). Additional guidelines were obtained from The National Guidelines Clearinghouse Internet site available at http://www.guideline.gov. Eligible guidelines met the Institute of Medicine definition and addressed a topic included in an economic analysis. Eligible economic analyses assessed interventions addressed in a guideline and predated the guideline by 1 or more years. Economic analyses were defined as incorporated in guideline development if 1) the economic analysis or the results were mentioned in the text or 2) listed as a reference. The quality of economic analyses was assessed using a structured scoring system.

RESULTS

Using guidelines as the unit of analysis, 9 of 35 (26%) incorporated at least 1 economic analysis of above-average quality in the text and 11 of 35 (31%) incorporated at least 1 in the references. Using economic analyses as the unit of analysis, 63 economic analyses of above-average quality had opportunities for incorporation in 198 instances across the 35 guidelines. Economic analyses were incorporated in the text in 13 of 198 instances (7%) and in the references in 18 of 198 instances (9%).

CONCLUSIONS

Rigorous economic analyses may be infrequently incorporated in the development of clinical practice guidelines. A systematic approach to guideline development should be used to ensure the consideration of economic analyses so that recommendations from guidelines may impact both the quality of care and the efficient allocation of resources.

Willingness-to-pay for colorectal cancer screening

Willingness-to-pay (WTP) techniques are increasingly being used in economic evaluation, as a means of assessing the value of new health care technologies. This paper presents the results of a WTP investigation of two types of screening for colorectal cancer. A questionnaire was issued to a general population via general practitioners (GPs), yielding a sample of approximately 2000 cases for analysis. Regression models demonstrated that WTP was significantly influenced by factors such as gender, income, age, risk perceptions, illness experiences and health beliefs. The median WTP for screening emerged as being pound30 or pound50, depending on the method used to elicit WTP, but independent of the screening protocol. Combining the results with those from related research, it emerged, first, that WTP subjects offered higher values for flexible sigmoidoscopy screening than the costs actually incurred by revealed preference studies and, second, they offered WTP values similar to the likely resource costs of the screening procedures.

Impact of systematic false-negative test results on the performance of faecal occult blood screening

The impact of systematic false-negative test results on mortality reduction and on programme sensitivity of annual faecal occult blood testing in ages 50-84 years is explored using a microsimulation model. We made calculations for test sensitivities of 80, 50 and 30%. In order to reproduce a cancer detection rate of 2.2 per 1000 at the first screening, the corresponding mean preclinical sojourn times had to be 1.42, 2.30 and 3.84 years, respectively. The fraction systematic results among the false-negative results is varied between 0 and 100%. With 80% test sensitivity, the reduction in mortality due to screening decreases from 25% without systematic results to 23% when all false-negative results are systematic and the programme sensitivity decreases from 63 to 58%. With 30% test sensitivity, mortality reduction decreases from 21 to 11% and programme sensitivity decreases from 52 to 27%. The impact of systematic false-negative test results is important if annual FOBT screening is considered.

Screening for colorectal cancer: what is the most cost-effective approach?

In Western countries, including Australia, colorectal cancer is the leading cause of cancer mortality in nonsmokers. Development of most colorectal cancers can be prevented by adenoma removal. The current screening strategies of faecal occult blood testing (FOBT), flexible sigmoidoscopy combined with FOBT and colonoscopy are all cost effective. In clinical practice, a range of options should be offered to allow for individual patients' preferences. A public education program is essential to the success of any screening strategy.

Effectiveness and economic impact of screening for colorectal cancer by mass fecal occult blood testing

OBJECTIVES

Fecal occult blood testing has been shown to reduce mortality from colorectal cancer in large randomized, controlled trials conducted in the United States, Denmark, and the United Kingdom, and mathematical simulation modeling found it to be cost-effective relative to other health care services. Before making a concerted effort to implement mass fecal occult blood testing based on this evidence alone, however, we considered it prudent to critically re-evaluate the effectiveness and economic impact of screening in the US population as a whole.

METHODS

To assess the effectiveness of screening, we projected published outcomes from each of the three large randomized controlled trials of fecal occult blood testing to the US population, as if each clinical trial had been done in the population as a whole. We then determined the resource costs of detection and treatment that would be associated with the outcomes predicted from each trial.

RESULTS

More than 1 million colorectal cancers could be expected to arise over 10 yr in the cohort of US residents eligible to enter a screening program in 1997, and trial outcomes indicate that > or = 60% of these cancers would be fatal. If the 60-67% compliance rate of the population-based randomized controlled trials were achieved, a fecal occult blood testing program would detect 30% of known colorectal cancers and save 100,000 lives over 10 yr. Screening would incur total costs of $3-4 billion over 10 yr, or $2,500 per life-year saved.

CONCLUSIONS

Mass fecal occult blood testing is cost-effective, and, although not inexpensive, many would consider the total cost acceptable. Even with a concerted effort to achieve compliance, however, the effectiveness of fecal occult blood testing would be limited to saving the lives of < or = 15% of those who otherwise would die from their cancer in the first 10 yr after beginning mass screening. The limitations of fecal occult blood testing suggest the need to further evaluate the role of endoscopy in screening, and to develop more effective, noninvasive screening tools.

Willingness to pay for a quality-adjusted life year: in search of a standard

Cost-benefit analysis (CBA) provides a clear decision rule: undertake an intervention if the monetary value of its benefits exceed its costs. However, due to a reluctance to characterize health benefits in monetary terms, users of cost-utility and cost-effectiveness analyses must rely on arbitrary standards (e.g., < $50,000 per QALY) to deem a program "cost-effective." Moreover, there is no consensus regarding the appropriate dollar value per QALY gained upon which to base resource allocation decisions. To address this, the authors determined the value of a QALY as implied by the value-of-life literature and compared this value with arbitrary thresholds for cost-effectiveness that have come into common use. A literature search identified 42 estimates of the value of life that were appropriate for inclusion. These estimates were classified by method: human capital (HK), contingent valuation (CV), revealed preference/job risk (RP-JR) and revealed preference/non-occupational safety (RP-S), and by U.S. or non-U.S. origin. After converting these value-of-life estimates to 1997 U.S. dollars, the life expectancy of the study population, age-specific QALY weights, and a 3% real discount rate were used to calculate the implied value of a QALY. An ordinary least-squares regression of the value of a QALY on study type and national origin explained 28.4% of the variance across studies. Most of the explained variance was attributable to study type; national origin did not significantly affect the values. Median values by study type were $24,777 (HK estimates), $93,402 (RP-S estimates), $161,305 (CV estimates), and $428,286 (RP-JR estimates). With the exception of HK, these far exceed the "rules of thumb" that are frequently used to determine whether an intervention produces an acceptable increase in health benefits in exchange for incremental expenditures.

Cost-utility of one-time colonoscopic screening for colorectal cancer at various ages

OBJECTIVE

One-time colonoscopy has been recommended as a possible colorectal cancer (CRC) screening strategy. Because the incidence of colorectal neoplasia increases with age, the effectiveness and cost of this strategy depend on the age at which screening occurs. The purpose of this study was to investigate the age-dependent cost-utility of one-time colonoscopic screening.

METHODS

We constructed a computer simulation model of the natural history of colorectal neoplasia. This model was used to compare the cost-utility of no screening and age-based strategies employing one-time colonoscopic screening (age ranges evaluated: 45-49, 50-54, 55-59, and 60-64 yr).

RESULTS

We determined that one-time colonoscopic screening in men age <60 yr and in women age <65 yr dominates never screening and screening at older ages. For both sexes, one-time colonoscopic screening between 50 and 54 yr of age is associated with a marginal cost-utility of less than $10,000 per additional quality-adjusted life-year compared to screening between 55 and 60 yr of age. One-time colonoscopic screening between 45 and 49 yr of age is either dominated (women) or associated with a marginal cost-utility of $69,000/per quality-adjusted life-year (men) compared to screening between 50 and 54 yr of age. The marginal cost-utility of one-time colonoscopic screening is relatively insensitive to plausible changes in the cost of colonoscopy, the cost of CRC treatment, the sensitivity of colonoscopy for colorectal neoplasia, the utility values representing the morbidity associated with the CRC-related health states, and the discount rate.

CONCLUSIONS

One-time colonoscopic screening between 50 and 54 yr of age is cost-effective compared to no screening and screening at older ages in both men and women. Screening in men between 45 and 49 yr of age may be cost-effective compared to screening between 50 and 54 yr of age depending on societal willingness to pay.

Screening for colorectal cancer

Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer deaths in the United States. Fortunately, both the incidence and mortality associated with the disease have declined during the past 2 decades. This is likely due, at least in part, to improved efforts at screening and more aggressive removal of adenomatous polyps. However, colorectal cancer screening is still generally underutilized. This article reviews the current status and future outlook for colorectal cancer screening, including a discussion of risk factors for the disease, its anatomic distribution, proposed mechanisms of development from adenomatous polyps, rationale for screening, and screening options. Published literature concerning the cost-effectiveness of colorectal cancer screening is also summarized. The article concludes with a discussion of the emerging consensus regarding the importance of and approaches to screening.